Pulp-canal file



W. W. BDLLS. PULP CANAL FILE. APPLICATION FILED DEC.23, 19x9.

Patented Sept. 14, 1920 UNITED ST TES PATENT oF I c j.

' WILLIAM w. BOLLS, or WASHINGTON, nrsrn'rc'r or comment.

PULP-CANAL FILE.

Specification of Letters Patent. Patented Sept, 14, 1920.

Application filed December 23, 1919. Serial no. 346,910.

To all whom it may concern:

Be it known that I, WILLIAM WV. BoLLs,

citizen of the United States, residing at lVashington, in the Districtof Columbia, have invented certain new and useful Improvements inPulp-Canal Files, of wh1ch the following is a specification.

This invention relates to pulp canal files and the primary objectthereof is to provide a file for use in the opening and cleaning ofcanals and the like which has a positive and effective abrasive orcutting action both during longitudinal reciprocation as well astransverse rotation of the file whereby to expedite removal of the pulpas well as to more effectively cleanse the canal.

A further object of the invention is to provide a file of this typewhich is formed with a multitude of individual cutting teeth Fig. 3, isa section on line 3'-3 of Fig. 2.

In proceeding in accordance with the present invention, a handle 1 isemployed to which the file 2. is suitably and rigidly affixed in anydesired. or preferred manner.

The file 2 is preferably formed of cold drawn tempered wire, for whichpurpose piano wire has by experiment been found suitable and maybe usedaccordingly. The

. file has a generally tapered conformation and upon its surface hasformed a multitude of teeth 3 which are provided by swaging i. 6..displacing or'mashing portions of the metal. The teeth 3 are all ofvarying types or characters and provide a cutting surface r which isjaggered and devoid of any regularity .offormation. Thus some teeth are.longer than others, some wider than others;

- some truly rectangular; some curved; some the axis.

and the like heretofore employed for purpose.

straight, and some of varying irregular shapes. In addition, the teethare disposed in varying relations to the longitudinal axis 'of the file;for example, some aline with V such axis; some traverse same at varyinginclinations and some are curved relative to Moreover, some teeth are'mo-re abrupt than others and some project beyond the file surface to agreater degree or extent than others. The object aimed at is to assurean effective and clean cut of the instrument regardless of whether sameis reciprocated longitudinally or transversely or continuously rotated.

The term scrapers asused contemplates cut, break down or have anabrasive action on the hard walls of the canal so as to en-1 70 Q large,shape and prepare the canal walls for.

filling. Accordingly the elements 3, must be stout and not subject tobending in any direction when the file is rotated orreciprocated. Thescrapers must cut into the hard any formation of the elements 3 whichwill walls of the canal and by disintegration of the walls effectenlarging thereof.

In actual practice, the "instrument has been found to be of markedadvantage and to afford removal of the walls of the pulp canal in a moreexpeditious, certain andeffective manner than with use 'of broache's theThe aforementioned irregular formation and disposition of the cuttingteeth alsopro.

vides a file of greater longevity, since the teeth by being variouslyformed and re lated are not subjected to like wear in use of theinstrument. In other words, the resultof wear will affect the variousteeth differently, so that all will not wear uniformly.

The mode of manufacture of the file results in a somewhat irregularlydefined spiral formation of certain teeth as Fig. 2'

suggests, thoughthis is not essential to'the success of'the invention. 7

What is claimed is:

1. A pulp canal 'file'forshaping, enlarge ing and cleaning the canalscrapers, which I are relatively short and closely relatedand saidscrapers being of different formations and having their cutting edgesvariously arrangedin irregular relation and at varying angles to thelongitudinal axis of the file and adapted to out both duringlongitudinal reciprocation as Well as transverse rotation of the file.

2. The method of making dental pulp canal files which consists inswaging a series of closely related and relatively short scrapers uponthe surface of a piece of tapered Wire With the scrapers variouslyarranged in irregular relation and at varying 10 angles to thelongitudinal axis of the Wire.

In testimony whereof I affix my signature.

WILLIAM W. BoLLs.

It is hereby certified that in Letters Patent N 0. 1,353,019, grantedSeptember 14,

1920, upon the application of William W. Bolls, of Washington, Districtof Columbis, for an improvement in Pulp-Canal Files, an error appears inthe printed specification requiring correction as follows: Page 1, line100, claim 1, after the Word canal insert thewords having a multitudeof; and that the said Letters Patent should be read with this correctiontherein that the same may conform to the record of the case in thePatent Office.

Signed and sealed this 19th day of October, A. D., 1920.

[SEAL] M. H. COULSTON,

Acting Commissioner of Patents. CI. 32-10.

